Machine-gun.



.A. B. REVELLI.

MACHINE GUN.

APPLICATION FILED DEC.8.19I5. 1,286,884. Patented Dec. 3, 1918.

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Eran/'02":

A. B. HEVELLI.

MACHINE GUN.

APPLICATIQN FILED nzcda. 1915..

1,286,884. Patented Dec. 3,1918.

HTS-SHEET 2.

A. B. REVELLI.

MACHINE GUN.

APPLICATION FILED DEC.8. 1915.

1,286,884. Patented Dec. 3,1918.

3 SHEETS-SHEET 3.

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AIBIEL BETEL REVELLI, OF TURIN, ITALY, ASSIGNOR TO OFFICINE DI VILLAIRPEROSA, 0F VILLAR, PEROSA, PINEBOLO, ITALY.

MACHINE-GUN.

mcaee Specification of Letters Patent.

, Patented Dec. 3,1918.

Application filed December 8, 1915. Serial No. 65,815.

To all whom it may concern:

Be it known that I, ABIEL BETEL REVELLI, major in the Italian Army,subject of the King of Italy, residing at Hotel Moderne, 39 Via XXSettembre, Turin, Italy, have invented certain new and usefulImprovements in Machine-Guns, of which the following is a specification.

This invention relates to machine uns provided with one, or more thanone arrel, the said gun being of a lighter weight and having a greaterrapidity of firing than those known heretofore.

In automatic firearms, hitherto known mechanical closing means(consisting of a bolt, spherical joint or the like) are used in orderthat at the moment of firing the breech block should be rigidlyconnected with the barrel. In small arms such as the Browning pistol orthe like, there is only a spring which conjointly with the mass of thebreech bolt afi'ords an adequate closure for small charges. In thepresent system, which may be called an intermediate one, veryconsiderable charges of powder may be used without having recourse tomechanical elements which always present a certain complication and aresubject to fracture.

I will describe with reference to the accompanying drawings aconstruction in accordance with this invention but I do not limit myselfto the precise construction described and illustrated.

Figures 1 and 2 are respectively a vertical section and a plan of aconstruction in accordance with this invention.

Figs. 3 and 4 are cross-sections taken on lines AA and B-Brespectively'of-Fig. 1. Fig. 5 is a perspective view of the gun. Fig. 6 shows adetail 'of the breech-block. Figs. 7 and 8 are a front elevation and aside elevation, respectively of one of the cartridge magazines.

Fig. 9 shows a detail of the elevator.

, Fig. 10 is a fragmental elevation showing theparts in aposition ofrecoil;

Fig. 11 is a similar view showing the parts at the commencement of thebreech closing operation;

Fig. 12 is a similar view showing the parts in elevation when the breechis completely closed, and

Fig. 13 is a perspective view of the breech block.

The machine gun which consists of two distinct but identical breech andfiring mechanisms, is provided with barrels 1 connected by a cross-bar 2having two handles 3, "and is mounted on a standard 4 with a Cardanjoint, havin two fixing handles 5 and 6 (Fig. 5) the ormer of whichserves for the training movement and the other one for the elevatingmovement.

Each of these breech and firing mechamsms comprises a hollow cylindricalbreech caslng 7 provlded with a lower lug 8 and screwed to thecorresponding rifled barrel 1. In the said breech casing there slideslongitudinally with a small rotary movement, a block 9 provided with aprojection 10 (here inafter called a shoe) carrying a handle 11. Thefront and rear faces of the shoe 10 are each formed with a ri ht handedhelical surface. The shoe 10 sli es in a slot 12 formed in the breechcasing, and rectilinear for the major portion of its length buthelicoidal at its forward end 13 wherein the said shoe is guided by itstwo helical faces.

The breech block 9 is hollow and in its interior there slides acylindrical percussion pin, or striker 14 provided with a projection 15which guides it in the rectangular portion of the slot 12. The frontface of the tooth 15 is formed with a left-handed helical surface 15bearin on the helical face 15 of the breech-block Figs. 10 to 13) inorder to insure that the striker may pass beyond the head of the saidblock when the latter is rotated into its closed position.

The percussion pin or striker it is hollow and contains in its interiora coiled sprin 16 controlling it. This spring is mounts on the guide-rod17 of the closure-plug 18 screwed into the breech-casing.

Around the forward end of the breech casing, a sleeve 19 is rotatablymounted, provided with projections for maneuverin puroses, serving tofix the magazines 20 uring ring; spring controlled stops (notillustrated forthe sake of simplicity) maintaining the said sleeve inboth positions.

The breech is provided with a stationary, or fixed, ejector 21 adaptedto engage a corresponding slot 22 formed in the breech block; the latteris provided with a levered extractor 23 pivoted at 25 and actuated by aspring 2 1.

The two mechanisms which as hereinbefore stated, are similar, or induplicate are connected at the forward end by means of a bentcross-member carrying the foresight 27 and at the rear by the cross-baror butt-end 2 carrying the annular backsight 27 with a graduated openingfor the .difierent distances of fining. The cross-member 2 is formed atits forward end with two cylindrical cavities into which the twobreeches penetrate and which are maintained therein by means of the pins28. Below the member 2 two triggers 29 are mounted (one on the right andthe other on the left) each having an- L-shape, the upper arm thereofbeing terminated by a release button 30 while the horizontal arm isterminated by a hook 31 which through an opening 32 formed in the breechcasing, engages into the notch 33 ofthe breech block when the latterisforced into its rear position; the spring 34 maintains the said lever inthis position until it is released by exerting a pressure on thecorresponding button 30.

The cross-member 2 is provided with a safety lever having spring-stops,formed by a controlling handle 35 and two lateral l'ocking arms 36,which, according to the position of the handle 35, engage underneaththebut-- ranged in double rows; it consists of a rectangular casing withrounded-0d edges and terminated 'at the bottom by two lips 39" curved insuch a manner as to retain the cartridges 40. In this tube there slidesa follower 41 9) having parallel divisions staggered relatively toeachother, which follower is forced toward the bottom by a suitablecoiled spring.

The gun operates in the nerr- By means of the handle 11, the breechblock 9 is drawn backward until it autofollowing manmeshes maticallyenga s the hook 31 and subsequently the sa ety lever 35-36 is broughtinto the locking position; the cartridge magazine is then placed on thebreech casing and secured thereto by means of'the sleeve 19; the gun istrained; the lever 35-36 is then rotated into its releasing position andthe button .30 depressed for firing. The breech block 9 and the striker1 1 then advance simultaneously under the action of the spring 16 andthe breech block pushes a cartridge into the loading chamber of thebarrel. At the end of its rectilinear travel,

the breech block is forced to turn to the right under the action of thehelical part 13 of the slot formed in the breech casing; while at thesame time the striker 14 also advances with respect to the breech block9 owing to the sliding of the helical surface 15 ofits tooth 15 on thecorresponding helical face of the notch formed in the breech block, andthe shot is fired. The gases of the explosive charge expel theprojectile in a forward direction while they tend to push back thebreech block. The latter offers a resistance for a moment (in view ofthe inertia of its mass and the resistance ofiered by the helical notch13 formed in the casing) and. subsequently recoils completely,withdrawing the empty cartridge with the hook of the extractor 23 untilthe said cartridge strikes the ejector 21 and is thereby ejected. If thefiring button 30 is held in a depressed posi-. tion, the same series of'movements takes place continually with great rapidity until thecartridge magazine is exhausted, the breech block always closinsimultaneously with the advancement of I e striker. The rear shoulder ofthe helical notch 13 acts as a stop during firing and as afriction-brake to reduce the speed during the first stage of the recoil.

Considerationof Figs. 10, 11 and 12 shows that relatively to the casing7 which may be regarded as fixed, the combinedsystem of the breech block9 and the firing pin 14, has only a single degree of freedom, so thatany displacement of one of these two elements, the breech block 9 andthe firing pin 14, definitely constrains the movement of the other.

The pitch angle of. engagement between the helical abutment 13 and theshoe 10 should be a. little steeper than the angle of repose. It isevident that if the pitch is very slight so that this engaging surfaceis nearly perpendicular to theaxis, the friction will be so great thatan axial thrust will not displace the shoe 10 from the abutment 13. Onthe other hand, if this pitch is very steep, the abutment 13will ofl'eralmost no resistance to hold the breech block against the recoil'of vthecartridge. The angle of repose is the criticafipitch at which an axialthrust on the breech block will barely sufiice to displace the shoe 10from the abutment 13. As already stated, the pitch should be a littlesteeper than this angle.

It is obvious that this firearm may be constructed with a greater numberof barrels than two, without however, departing from the rincipleunderlyingthe invention.

Finally, it will be noted that instead of the support 4 the gun with oneor more barrels may be mounted after the manner of a rifle in order thatit may be fired from the V shoulder.

What I claim and desire to secure by Letters Patent of the United Statesis 1. A machine gun of the class described, comprising a casing,provided with a longitudinal slot terminating in a helical notch at oneend, a reciprocatory breech block within said casing, a helical notch atone end of said breech block, means on said breech block to engage thelongitudinal slot and helical notch of the casing, the pitch of saidhelical notch of the casing being steeper than the angle of repose ofsaid means therein, a plunger within said breech block, means on saidplunger to engage the helical notch of the breech block, and means toreciprocate the breech block and the plunger relative to the casing.

2. A machine gun of the class described, comprising a casing providedwith a longitudinal slot terminating in a helical notch,

.a reciprocatory b-reechblock within said casing, a shoe mounted on saidbreech block to engage the longitudinal slot and' the helical notch ofthe casing, the pitch of said helical notch of the casing being steeperthan the angle of repose of said s hoe therein, said shoe having two ofits faces shaped to conform with the contour of the opposing edges ofthe helical notch of the casing, a helical notch in the rear end of thebreech block, a plunger within said breech block, a lug mounted on saidplunger to engage the helical notch of the breech block, said lug havingits engaging face shaped to conform to the helical edge of'the notch ofthe breech block, and means to reciprocate said plunger and said breechblock within the casing.

3. In a machine gun of the class in which the recoil of the cartridgeacts directly to open the breech, oblique locking means for the breechblock between the same and the casin means to advance the firing pinrelative y to the breech block simultaneously with'the closing andlocking movement of the latter and to continue the locking movement ofthe breech block in substantial degree during the entire advancemovement of the firing pin.

4. In a machine gun of the class in which the recoil of the cartridgeacts directly to open the breech, oblique locking means for the breechblock between the same and the casing, means to advance the firing pinrelatively to the breech block simultaneously with the rotary lockingmovement of the latter and to continue the locking movement of thebreech block in substantial degree during theentire advance movement ofthe firing pin.

5. A machine gun of the class in which the recoil of the cartridge actsdirectly to open the breech, comprising a casing, a breech block withinsaid casing adapted to abut against the cartridge, a plunger within saidbreech block, a firing pin mounted on said plunger, means to advance theplunger and the firing pin for firing, meanson said plunger to engagethe breech block and advance the same, oblique means steeper than theangle of repose to lock the breech block when in the firing position andto break the initial recoil of the breech block following the dischargeof the gun. g

6. A machine gun of the class described, comprising a casing, a breechblock, within said casing, an aperture in said breech block to coincidewith an aperture in the casing when said breech block is in its recoiledposition, a closure plug in the end of said casing, a cap inclosing theend of the casing and the closure plug, a bell crank lever pivoted onsaid cap, one arm of said bell crank lever protruding into the aperturein the casing, and engaging the breech block by means of its aperturewhen said breech block is in its recoiled position, the other end of thebell crank lever terminating adjacent the end of the cap inclosing thecasing, and means interposed between the cap and one lever arm to retainthe other lever arm in constant engagement with the aperture of thecasing. I

7. A machine gun of the class described,

comprising a casing, a closure plug in one end of said casing, a capinclosing said plug and enveloping the end of said casing, a guide pinmounted onsaid closure plug, a helical spring loosely mounted on saidguide pin, a breech block within the casing, a plunger within saidbreech block, a firing pin mounted on said plunger, said plunger rotaryclosing movement of the breech block in substantial degree as long asthe advance of the firing pin relative thereto continues.

9. In a machine gun of the class in which the recoil of the cartridgeacts directly to open the breech, a casing, a breech block, a percussionpin, a spring acting between said casing and block and pin, and means toconstrain the block and the pin to move relatively to one another but toreciprocate simultaneously in the casing and to reverse theirreciprocatory movement simultaneously.

10; In a machine gun of the class in which the recoil of the cartridgeacts directly to open the breech, a casing, a breech block adapted toabut against the cartridge, a percussion pin, a spring acting betweensaid casing and block and pin, and means to constrain the block and thepin to reciprocate simultaneously in the casing and to increase thelongitudinal movement of the pin relatively to the block. at the breechclosing end of their travel.

11. In a machine gun of the class in which the recoil of the cartridgeacts directly to open the breech, a casing, a breechblock adapted toabut against the cartridge, a percussion pin, a spring acting betweensaid casing and block and pin, an inclined abutment carried by thecasing, a shoe carried 'bythe block to engage the abutment, and meansconstraining said block and pin simultaneously to engage the shoe withthe abutment and to advance the percussion pin relatively to the block.

, 12. In a machine gun of the class in which the recoil of the cartridgeacts directly to open the breech, a casing, a breech block, a percussionpin, a spring acting between said casing and block and pin, meansconnecting the block and pin so they have a definite relative positionfor each position of 'theblock in the casing, an inclined abutmentcarried by the casing, a shoe carried by the block to engage theabutment, and means constraining said block and pin simultaneously tomove the block helically to engage the shoe with the abutment and toadvance the percussion pin relatively to the block.

casing and block and pin, means to constrain the block and 'pin toreciprocate as a unit when the block is withdrawn from its breechclosing position, an abutment carried by the casing, and meansconstraining said block and pin to engage the block with the abut mentat the breech closing end of its travel and simultaneously to advancethe pin relatively to the bloc 14:. In a machine gun of the class inwhich the recoil of the cartridge acts directly to open the breech, acasing, a breech block adapted to abut against the cartridge, apercussion pin, a spring acting between said casing and block and pin,and means constraining said block and pin to advance the block byhelical movement to breech closing and locking position, andsimultaneously to advance the pin relatively to the block.

15. In a machine gun, a casing, a breech block, a percussion pin, saidblock and pin engaging one another along a helical surface,

a spring acting between the casing and said I block and pin, means toprevent rotative movement of bothblock and pin when away block, apercussion pin, a spring acting between the casing and said block andpin,

means to prevent rotative movement of the block and pin when away frombreech closing position, means disposed on the casing and blockpermitting helical movement of the block at breech closing position, andmeans disposed on the block and pin permittingrelative helical movementbetween them at an opposite inclination atbreech closing position, saidmeans preventing other than helical movement between the block and pin.

In testimony whereof I afiix my signature inpresence of two witnesses.

ABIEL BETEL REVELLI. Witnesses a Y C. S. TEYLES,

SIG. Fnnnnooro JACOBACCI.

said helical surface,

